The invention provides a novel binder resin composition with good adherence onto prime materials of polyolefin, poly (vinyl chloride), polycarbonate, PET, ABS and nylon, and also with excellent solvent solubility.A binder resin composition characterized by being chlorinated propylenic random copolymer with weight average molecular weight of 3000 to 250000, wherein propylenic random copolymer with melting point (Tm) measured by differential scanning calorimeter (DSC) of 115 to 165.degree. C. obtained by copolymerizing propylene with other .alpha.-olefin in the coexistence of metallocene type catalyst is chlorinated to chlorine content of 10 to 40% by weight, after thermal degradation or directly without thermal degradation, and/or a binder resin composition characterized by containing carboxyl group-containing chlorinated propylenic random copolymer with weight average molecular weight of 30000 to 220000, wherein propylenic random copolymer with melting point (Tm) measured by differential scanning calorimeter (DSC) of 115 to 165.degree. C. obtained by copolymerizing propylene with other .alpha.-olefin in the coexistence of metallocene type catalyst is grafted with .alpha.,.beta.-unsaturated carboxylic acid or its anhydride in amounts of 0.1 to 20% by weight, after thermal degradation or directly without thermal degradation, and then chlorinated to chlorine content of 10 to 40% by weight, stabilizer and organic solvent.